VSS Unity will fire its motor after being carried aloft and released by a carrier plane, WhiteKnightTwo, which will take off from the Mojave Air and Space Port in Mojave, California.

Virgin Galactic has given few details about the test but said it should yield more information about the craft's center of gravity — which is of critical importance to a vehicle's handling characteristics.

"We'll have several minutes of weightlessness to enjoy before we come back down," Virgin Galactic's chief pilot, David Mackay, said in a video posted before the planned test. "On the way back down in feather configuration, we'll be looking at how it handles in the feather, how easy it is to control in the feather."